Gerry ‘The Monk’ Hutch has been arrested in Spain as part of an international police investigation into suspected money laundering.
Mr Hutch, 61, was arrested along with other relatives in Spain and is being questioned by authorities.
It comes a day after a number of searches were carried out in Ireland and Spain as part of an investigation into transnational organised crime.
Garda Commissioner Drew Harris said the searches and arrest follow the sharing of information and evidence between Irish and Spanish police.
Speaking at the Garda headquarters in Dublin, Mr Harris said: “There’s a judicial process ongoing with the Spanish authorities, so I cannot comment then on the specifics of yesterday’s operations and what’s going to unfold over the next couple of days.
“But I can say we’ve been engaged with Guardia Civil over a number of years, over two years, closely in terms of sharing information and then sharing evidence.
“We will see today and over the coming days, just what the immediate outturns are of that investigation.
“It’s another organised crime group. They’re a very well known one, and so there is an element of notoriety in respect of them.
“But beyond that then, is the extent of the criminality that they are engaged in.
“We’ve been involved in a long term and very thorough, focused investigation in respect of that organised crime group, and that has meant that we’ve worked with our international partners in trying to bring to an end the criminality that the overall organised crime groups involved in.
“It is significant in terms of our cooperation with the Spanish authorities in this case and Europol. As the next couple of days unfold, will see some of the out turn of that.”
10 searches were conducted in Spain on Wednesday morning while gardaí from the Garda National Bureau of Criminal Investigation (GNBCI) are in Spain supporting the Guardia Civil.
An officer from the Guardia Civil attended the search of a residential property in Dublin on Wednesday, following a request by the Spanish authorities.
A close associate of Hutch is also understood to have been held by police.
Hutch's detainment follows an operation spanning more than two years by Guardia Civil and An Garda Síochána.
The operation comes days after the veteran criminal garnered extensive media publicity over reports that he was considering running in the upcoming general election.
Hutch has made Lanzarote a home-from-home over the last 10 years and is believed to have a number of properties and business interests there.
It is the second time Hutch has been the target of Guardia Civil, which tracked him down in August 2021 to Fuengirola on the Costa del Sol on foot of an EU extradition warrant from Ireland.
Hutch, a father of four, was extradited back to Ireland where he was charged with the murder of David Byrne at the Regency Hotel in February 2016.
Daniel Kinahan, the operational head of the Kinahan crime cartel, narrowly escaped being shot in the infamous attack.
